In the past 5 years, two well-liked and respected members of the Oracle APEX team, Carl Backstrom and Scott Spadafore, passed away suddenly (at different times). They are still missed, by their families and by this community.
Fortunately, other members of this community - specifically, the co-authors of the Apress book Expert Oracle Application Express - are now donating all their royalties, all 100% of them, to charities that support the families of Carl and Scott. (There is more back story in John Scott's blog post here.)
So, if you were considering buying this book, now would be a good time. And if you weren't, now would be a good time to re-consider!